From 3a0b6d584969f2813970e432d029e4a8d1743e4c Mon Sep 17 00:00:00 2001
From: Gabe Cook <gabe565@gmail.com>
Date: Thu, 25 Apr 2024 23:09:44 -0500
Subject: [PATCH] feat: Initial commit

---
 .changelog-generator.yaml   | 14 ++++++
 .dockerignore               |  9 ++++
 .env.example                |  2 +
 .github/CODEOWNERS          |  1 +
 .github/renovate.json       | 16 +++++++
 .github/workflows/build.yml | 90 +++++++++++++++++++++++++++++++++++++
 .gitignore                  | 12 +++++
 .golangci.yaml              | 88 ++++++++++++++++++++++++++++++++++++
 .pre-commit-config.yaml     |  7 +++
 Dockerfile                  | 56 +++++++++++++++++++++++
 cmd/cmd.go                  | 29 ++++++++++++
 cmd/cmd_test.go             | 25 +++++++++++
 compose.yaml                | 18 ++++++++
 go.mod                      | 22 +++++++++
 go.sum                      | 45 +++++++++++++++++++
 internal/alert/event.go     | 58 ++++++++++++++++++++++++
 internal/alert/handler.go   | 29 ++++++++++++
 internal/config/config.go   | 10 +++++
 internal/config/context.go  | 16 +++++++
 internal/config/flags.go    | 13 ++++++
 internal/config/load.go     | 29 ++++++++++++
 main.go                     | 13 ++++++
 payloads/alarm.json         | 42 +++++++++++++++++
 payloads/composite.json     | 30 +++++++++++++
 24 files changed, 674 insertions(+)
 create mode 100644 .changelog-generator.yaml
 create mode 100644 .dockerignore
 create mode 100644 .env.example
 create mode 100644 .github/CODEOWNERS
 create mode 100644 .github/renovate.json
 create mode 100644 .github/workflows/build.yml
 create mode 100644 .gitignore
 create mode 100644 .golangci.yaml
 create mode 100644 .pre-commit-config.yaml
 create mode 100644 Dockerfile
 create mode 100644 cmd/cmd.go
 create mode 100644 cmd/cmd_test.go
 create mode 100644 compose.yaml
 create mode 100644 go.mod
 create mode 100644 go.sum
 create mode 100644 internal/alert/event.go
 create mode 100644 internal/alert/handler.go
 create mode 100644 internal/config/config.go
 create mode 100644 internal/config/context.go
 create mode 100644 internal/config/flags.go
 create mode 100644 internal/config/load.go
 create mode 100644 main.go
 create mode 100644 payloads/alarm.json
 create mode 100644 payloads/composite.json

diff --git a/.changelog-generator.yaml b/.changelog-generator.yaml
new file mode 100644
index 0000000..54674fc
--- /dev/null
+++ b/.changelog-generator.yaml
@@ -0,0 +1,14 @@
+# yaml-language-server: $schema=https://gabe565.github.io/changelog-generator/config.schema.json
+filters:
+  exclude:
+    - "^docs"
+    - "^test"
+groups:
+  - title: Features
+    order: 0
+    regexp: "^(feat)"
+  - title: Fixes
+    order: 1
+    regexp: "^(fix|perf)"
+  - title: Others
+    order: 999
diff --git a/.dockerignore b/.dockerignore
new file mode 100644
index 0000000..bae4df7
--- /dev/null
+++ b/.dockerignore
@@ -0,0 +1,9 @@
+.changelog-generator.yaml
+.git/
+.github/
+.gitignore
+.golangci.yaml
+.idea/
+.pre-commit-config.yaml
+README.md
+payloads/
diff --git a/.env.example b/.env.example
new file mode 100644
index 0000000..3887e1d
--- /dev/null
+++ b/.env.example
@@ -0,0 +1,2 @@
+SLACK_API_TOKEN=
+SLACK_CHANNEL=
diff --git a/.github/CODEOWNERS b/.github/CODEOWNERS
new file mode 100644
index 0000000..1a1a071
--- /dev/null
+++ b/.github/CODEOWNERS
@@ -0,0 +1 @@
+* @clevyr/devops
diff --git a/.github/renovate.json b/.github/renovate.json
new file mode 100644
index 0000000..0c42e3b
--- /dev/null
+++ b/.github/renovate.json
@@ -0,0 +1,16 @@
+{
+  "$schema": "https://docs.renovatebot.com/renovate-schema.json",
+  "extends": [
+    "local>clevyr/renovate-config"
+  ],
+  "regexManagers": [
+    {
+      "fileMatch": "Dockerfile$",
+      "matchStrings": [
+        "ARG RIE_VERSION=(?<currentValue>.*)"
+      ],
+      "datasourceTemplate": "github-releases",
+      "depNameTemplate": "aws/aws-lambda-runtime-interface-emulator"
+    }
+  ]
+}
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
new file mode 100644
index 0000000..978eabf
--- /dev/null
+++ b/.github/workflows/build.yml
@@ -0,0 +1,90 @@
+name: Build
+
+on: push
+
+jobs:
+  lint:
+    name: Lint
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+          cache: false
+      - name: Lint
+        uses: golangci/golangci-lint-action@v5
+
+  test:
+    name: Test
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+      - name: Test
+        run: go test ./...
+
+  build:
+    name: Build Image
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: |
+            ghcr.io/clevyr/lambda-cloudwatch-slack
+          tags: |
+            type=raw,priority=1000,value=latest,enable=${{ startsWith(github.ref, 'refs/tags/v') }}
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=semver,pattern={{major}}
+            type=raw,value=beta,enable=${{ github.ref_name == 'main' }}
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+      - name: Set up Buildx
+        uses: docker/setup-buildx-action@v3
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ github.token }}
+      - name: Build and Push
+        id: docker_build
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          pull: true
+          push: ${{ steps.meta.outputs.tags != '' }}
+          platforms: linux/arm64
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
+
+  release:
+    name: Release
+    runs-on: ubuntu-latest
+    needs: [lint, test, build]
+    if: startsWith(github.ref, 'refs/tags/v')
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - name: Generate Changelog
+        id: changelog
+        uses: gabe565/changelog-generator@v0
+      - name: Release
+        uses: softprops/action-gh-release@v2
+        with:
+          body: ${{ steps.changelog.outputs.changelog }}
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..9c4664b
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,12 @@
+# Editor
+.idea
+
+# Compiled
+coverage.out
+dist/
+lambda-cloudwatch-slack
+out/
+
+# Config
+.env*
+!.env.example
diff --git a/.golangci.yaml b/.golangci.yaml
new file mode 100644
index 0000000..594c368
--- /dev/null
+++ b/.golangci.yaml
@@ -0,0 +1,88 @@
+run:
+  timeout: 5m
+
+issues:
+  max-same-issues: 50
+  exclude-rules:
+    - path: "_test\\.go"
+      linters:
+        - dupl
+
+linters:
+  enable:
+    - asasalint
+    - asciicheck
+    - bidichk
+    - bodyclose
+    - copyloopvar
+    - decorder
+    - dupl
+    - durationcheck
+    - errcheck
+    - errname
+    - errorlint
+    - execinquery
+    - exportloopref
+    - forbidigo
+    - gci
+    - ginkgolinter
+    - gocheckcompilerdirectives
+    - gochecknoglobals
+    - gochecknoinits
+    - gochecksumtype
+    - goconst
+    - gocritic
+    - gocyclo
+    - godox
+    - goerr113
+    - gofumpt
+    - goheader
+    - goimports
+    - gomoddirectives
+    - gomodguard
+    - goprintffuncname
+    - gosec
+    - gosimple
+    - gosmopolitan
+    - govet
+    - importas
+    - inamedparam
+    - ineffassign
+    - interfacebloat
+    - intrange
+    - loggercheck
+    - makezero
+    - mirror
+    - musttag
+    - nakedret
+    - nilerr
+    - nilnil
+    - noctx
+    - nolintlint
+    - nonamedreturns
+    - nosprintfhostport
+    - paralleltest
+    - perfsprint
+    - prealloc
+    - predeclared
+    - promlinter
+    - protogetter
+    - reassign
+    - revive
+    - rowserrcheck
+    - sloglint
+    - spancheck
+    - sqlclosecheck
+    - staticcheck
+    - stylecheck
+    - tenv
+    - testableexamples
+    - testifylint
+    - typecheck
+    - unconvert
+    - unparam
+    - unused
+    - usestdlibvars
+    - wastedassign
+    - whitespace
+    - zerologlint
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
new file mode 100644
index 0000000..70fecf5
--- /dev/null
+++ b/.pre-commit-config.yaml
@@ -0,0 +1,7 @@
+repos:
+  - repo: https://github.com/TekWizely/pre-commit-golang
+    rev: v1.0.0-rc.1
+    hooks:
+      - id: go-mod-tidy-repo
+      - id: golangci-lint-mod
+        args: [--fix]
diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 0000000..dbc3862
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,56 @@
+#syntax=docker/dockerfile:1.7
+
+FROM --platform=$BUILDPLATFORM golang:1.22.2-alpine as builder
+WORKDIR /app
+
+COPY go.mod go.sum ./
+RUN go mod download
+
+COPY cmd cmd
+COPY internal internal
+COPY *.go ./
+# Set Golang build envs based on Docker platform string
+ARG TARGETPLATFORM
+RUN --mount=type=cache,target=/root/.cache <<EOT
+  set -eux
+
+  case "$TARGETPLATFORM" in
+    'linux/amd64') export GOARCH=amd64 ;;
+    'linux/arm/v6') export GOARCH=arm GOARM=6 ;;
+    'linux/arm/v7') export GOARCH=arm GOARM=7 ;;
+    'linux/arm64') export GOARCH=arm64 ;;
+    *) echo "Unsupported target: $TARGETPLATFORM" && exit 1 ;;
+  esac
+
+  export CGO_ENABLED=0
+  go build -ldflags='-w -s' -tags lambda.norpc -trimpath -o cloudwatch-slack-alerts .
+EOT
+
+FROM alpine:3.19 AS rie
+WORKDIR /app
+ARG TARGETPLATFORM
+ARG RIE_VERSION=v1.18
+RUN <<EOT
+  set -eux
+
+  case "$TARGETPLATFORM" in
+    'linux/amd64') export SUFFIX=x86_64 ;;
+    'linux/arm64') export SUFFIX=arm64 ;;
+    *) echo "Unsupported target: $TARGETPLATFORM" && exit 1 ;;
+  esac
+
+  wget \
+    -O aws-lambda-rie \
+    "https://github.com/aws/aws-lambda-runtime-interface-emulator/releases/download/$RIE_VERSION/aws-lambda-rie-$SUFFIX"
+  chmod +x aws-lambda-rie
+EOT
+
+FROM alpine:3.19 AS base
+WORKDIR /app
+COPY --from=builder /app/cloudwatch-slack-alerts .
+
+FROM base AS local
+COPY --from=rie /app/aws-lambda-rie .
+
+FROM base
+CMD ["./cloudwatch-slack-alerts"]
diff --git a/cmd/cmd.go b/cmd/cmd.go
new file mode 100644
index 0000000..e19a7ad
--- /dev/null
+++ b/cmd/cmd.go
@@ -0,0 +1,29 @@
+package cmd
+
+import (
+	"context"
+
+	"github.com/aws/aws-lambda-go/lambda"
+	"github.com/clevyr/cloudwatch-slack-alerts/internal/alert"
+	"github.com/clevyr/cloudwatch-slack-alerts/internal/config"
+	"github.com/spf13/cobra"
+)
+
+func NewCommand() *cobra.Command {
+	conf := config.New()
+
+	cmd := &cobra.Command{
+		Use:   "cloudwatch-slack-alerts",
+		Short: "Send AWS CloudWatch notifications to a Slack channel using Lambda",
+		PreRunE: func(cmd *cobra.Command, _ []string) error {
+			return conf.Load(cmd)
+		},
+		Run: func(_ *cobra.Command, _ []string) {
+			lambda.Start(alert.Handler(conf))
+		},
+	}
+
+	conf.RegisterFlags(cmd)
+	cmd.SetContext(config.NewContext(context.Background(), conf))
+	return cmd
+}
diff --git a/cmd/cmd_test.go b/cmd/cmd_test.go
new file mode 100644
index 0000000..6d31ef5
--- /dev/null
+++ b/cmd/cmd_test.go
@@ -0,0 +1,25 @@
+package cmd
+
+import (
+	"testing"
+
+	"github.com/clevyr/cloudwatch-slack-alerts/internal/config"
+	"github.com/spf13/cobra"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestCmdDbFlags(t *testing.T) {
+	t.Setenv("SLACK_API_TOKEN", "123")
+	t.Setenv("SLACK_CHANNEL", "alerts")
+
+	rootCmd := NewCommand()
+	rootCmd.Run = func(_ *cobra.Command, _ []string) {}
+
+	require.NoError(t, rootCmd.Execute())
+
+	conf, ok := config.FromContext(rootCmd.Context())
+	require.True(t, ok)
+	assert.Equal(t, "123", conf.SlackAPIToken)
+	assert.Equal(t, "alerts", conf.SlackChannel)
+}
diff --git a/compose.yaml b/compose.yaml
new file mode 100644
index 0000000..66bc03c
--- /dev/null
+++ b/compose.yaml
@@ -0,0 +1,18 @@
+services:
+  app:
+    image: ghcr.io/clevyr/cloudwatch-slack-alerts:local
+    build:
+      context: .
+      target: local
+    env_file:
+      - .env
+    entrypoint:
+      - ./aws-lambda-rie
+    command:
+      - ./cloudwatch-slack-alerts
+    ports:
+      - 127.0.0.1:9000:8080
+    develop:
+      watch:
+        - action: rebuild
+          path: .
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..b0e5be4
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,22 @@
+module github.com/clevyr/cloudwatch-slack-alerts
+
+go 1.22.2
+
+require (
+	github.com/aws/aws-lambda-go v1.47.0
+	github.com/slack-go/slack v0.12.5
+	github.com/spf13/cobra v1.8.0
+	github.com/spf13/pflag v1.0.5
+	github.com/stretchr/testify v1.9.0
+)
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/gorilla/websocket v1.4.2 // indirect
+	github.com/inconshreveable/mousetrap v1.1.0 // indirect
+	github.com/kr/pretty v0.3.0 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/rogpeppe/go-internal v1.12.0 // indirect
+	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..681ffac
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,45 @@
+github.com/aws/aws-lambda-go v1.47.0 h1:0H8s0vumYx/YKs4sE7YM0ktwL2eWse+kfopsRI1sXVI=
+github.com/aws/aws-lambda-go v1.47.0/go.mod h1:dpMpZgvWx5vuQJfBt0zqBha60q7Dd7RfgJv23DymV8A=
+github.com/cpuguy83/go-md2man/v2 v2.0.3/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
+github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/go-test/deep v1.0.4 h1:u2CU3YKy9I2pmu9pX0eq50wCgjfGIt539SqR7FbHiho=
+github.com/go-test/deep v1.0.4/go.mod h1:wGDj63lr65AM2AQyKZd/NYHGb0R+1RLqB8NKt3aSFNA=
+github.com/google/go-cmp v0.5.7 h1:81/ik6ipDQS2aGcBfIN5dHDB36BwrStyeAQquSYCV4o=
+github.com/google/go-cmp v0.5.7/go.mod h1:n+brtR0CgQNWTVd5ZUFpTBC8YFBDLK/h/bpaJ8/DtOE=
+github.com/gorilla/websocket v1.4.2 h1:+/TMaTYc4QFitKJxsQ7Yye35DkWvkdLcvGKqM+x0Ufc=
+github.com/gorilla/websocket v1.4.2/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
+github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
+github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
+github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
+github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
+github.com/kr/pretty v0.3.0 h1:WgNl7dwNpEZ6jJ9k1snq4pZsg7DOEN8hP9Xw0Tsjwk0=
+github.com/kr/pretty v0.3.0/go.mod h1:640gp4NfQd8pI5XOwp5fnNeVWj67G7CFk/SaSQn7NBk=
+github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/rogpeppe/go-internal v1.6.1/go.mod h1:xXDCJY+GAPziupqXw64V24skbSoqbTEfhy4qGm1nDQc=
+github.com/rogpeppe/go-internal v1.12.0 h1:exVL4IDcn6na9z1rAb56Vxr+CgyK3nn3O+epU5NdKM8=
+github.com/rogpeppe/go-internal v1.12.0/go.mod h1:E+RYuTGaKKdloAfM02xzb0FW3Paa99yedzYV+kq4uf4=
+github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
+github.com/slack-go/slack v0.12.5 h1:ddZ6uz6XVaB+3MTDhoW04gG+Vc/M/X1ctC+wssy2cqs=
+github.com/slack-go/slack v0.12.5/go.mod h1:hlGi5oXA+Gt+yWTPP0plCdRKmjsDxecdHxYQdlMQKOw=
+github.com/spf13/cobra v1.8.0 h1:7aJaZx1B85qltLMc546zn58BxxfZdR/W22ej9CFoEf0=
+github.com/spf13/cobra v1.8.0/go.mod h1:WXLWApfZ71AjXPya3WOlMsY9yMs7YeiHhFVlvLyhcho=
+github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
+github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
+github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
+github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
+gopkg.in/errgo.v2 v2.1.0/go.mod h1:hNsd1EY+bozCKY1Ytp96fpM3vjJbqLJn88ws8XvfDNI=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
diff --git a/internal/alert/event.go b/internal/alert/event.go
new file mode 100644
index 0000000..38e6803
--- /dev/null
+++ b/internal/alert/event.go
@@ -0,0 +1,58 @@
+package alert
+
+import (
+	"net/url"
+	"strconv"
+
+	"github.com/aws/aws-lambda-go/events"
+	"github.com/slack-go/slack"
+)
+
+type CloudWatchAlarmSNSPayload struct {
+	events.CloudWatchAlarmSNSPayload
+}
+
+func (event CloudWatchAlarmSNSPayload) SlackMsg() []slack.MsgOption {
+	var color string
+	switch event.NewStateValue {
+	case "ALARM":
+		color = "danger"
+	case "OK":
+		color = "warning"
+	default:
+		color = "OK"
+	}
+
+	consoleURL := url.URL{
+		Scheme:   "https",
+		Host:     "console.aws.amazon.com",
+		Path:     "/cloudwatch/home",
+		RawQuery: "region=" + event.Region,
+		Fragment: "alarm:alarmFilter=ANY;name=" + event.AlarmName,
+	}
+
+	return []slack.MsgOption{
+		slack.MsgOptionText("*AWS CloudWatch Notification*", false),
+		slack.MsgOptionAttachments(
+			slack.Attachment{
+				Color: color,
+				Fields: []slack.AttachmentField{
+					{Title: "Alarm Name", Value: event.AlarmName, Short: true},
+					{Title: "Alarm Description", Value: event.AlarmDescription, Short: true},
+					{
+						Title: "Trigger",
+						Value: event.Trigger.Statistic + " " +
+							event.Trigger.MetricName + " " +
+							event.Trigger.ComparisonOperator + " " +
+							strconv.FormatFloat(event.Trigger.Threshold, 'f', 2, 64) + " for " +
+							strconv.Itoa(int(event.Trigger.EvaluationPeriods)) + " period(s) of " +
+							strconv.Itoa(int(event.Trigger.Period)) + " seconds.",
+					},
+					{Title: "Old State", Value: event.OldStateValue, Short: true},
+					{Title: "Current State", Value: event.NewStateValue, Short: true},
+					{Title: "Link to Alarm", Value: consoleURL.String()},
+				},
+			},
+		),
+	}
+}
diff --git a/internal/alert/handler.go b/internal/alert/handler.go
new file mode 100644
index 0000000..5121e69
--- /dev/null
+++ b/internal/alert/handler.go
@@ -0,0 +1,29 @@
+package alert
+
+import (
+	"context"
+
+	"github.com/clevyr/cloudwatch-slack-alerts/internal/config"
+	"github.com/slack-go/slack"
+)
+
+type HandlerFunc func(ctx context.Context, event CloudWatchAlarmSNSPayload) error
+
+func Handler(conf *config.Config) HandlerFunc {
+	var api *slack.Client
+	return func(ctx context.Context, event CloudWatchAlarmSNSPayload) error {
+		if conf.SlackAPIToken != "" {
+			if api == nil {
+				api = slack.New(conf.SlackAPIToken)
+			}
+
+			opts := event.SlackMsg()
+			opts = append(opts, slack.MsgOptionAsUser(true))
+			_, _, err := api.PostMessageContext(ctx, conf.SlackChannel, opts...)
+			if err != nil {
+				return err
+			}
+		}
+		return nil
+	}
+}
diff --git a/internal/config/config.go b/internal/config/config.go
new file mode 100644
index 0000000..0595dc0
--- /dev/null
+++ b/internal/config/config.go
@@ -0,0 +1,10 @@
+package config
+
+type Config struct {
+	SlackAPIToken string
+	SlackChannel  string
+}
+
+func New() *Config {
+	return &Config{}
+}
diff --git a/internal/config/context.go b/internal/config/context.go
new file mode 100644
index 0000000..a2a7e94
--- /dev/null
+++ b/internal/config/context.go
@@ -0,0 +1,16 @@
+package config
+
+import "context"
+
+type ctxKey uint8
+
+const configKey ctxKey = iota
+
+func NewContext(ctx context.Context, conf *Config) context.Context {
+	return context.WithValue(ctx, configKey, conf)
+}
+
+func FromContext(ctx context.Context) (*Config, bool) {
+	conf, ok := ctx.Value(configKey).(*Config)
+	return conf, ok
+}
diff --git a/internal/config/flags.go b/internal/config/flags.go
new file mode 100644
index 0000000..8f4ab7b
--- /dev/null
+++ b/internal/config/flags.go
@@ -0,0 +1,13 @@
+package config
+
+import "github.com/spf13/cobra"
+
+const (
+	SlackAPITokenFlag = "slack-api-token"
+	SlackChannelFlag  = "slack-channel"
+)
+
+func (c *Config) RegisterFlags(cmd *cobra.Command) {
+	cmd.Flags().StringVar(&c.SlackAPIToken, SlackAPITokenFlag, "", "Slack API token")
+	cmd.Flags().StringVar(&c.SlackChannel, SlackChannelFlag, "", "Slack channel")
+}
diff --git a/internal/config/load.go b/internal/config/load.go
new file mode 100644
index 0000000..9ca6a49
--- /dev/null
+++ b/internal/config/load.go
@@ -0,0 +1,29 @@
+package config
+
+import (
+	"errors"
+	"os"
+	"strings"
+
+	"github.com/spf13/cobra"
+	"github.com/spf13/pflag"
+)
+
+func (c *Config) Load(cmd *cobra.Command) error {
+	var errs []error
+	cmd.Flags().VisitAll(func(f *pflag.Flag) {
+		if !f.Changed {
+			key := flagToEnv(f.Name)
+			if val, ok := os.LookupEnv(key); ok {
+				if err := f.Value.Set(val); err != nil {
+					errs = append(errs, err)
+				}
+			}
+		}
+	})
+	return errors.Join(errs...)
+}
+
+func flagToEnv(f string) string {
+	return strings.ToUpper(strings.ReplaceAll(f, "-", "_"))
+}
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..2c53f5d
--- /dev/null
+++ b/main.go
@@ -0,0 +1,13 @@
+package main
+
+import (
+	"os"
+
+	"github.com/clevyr/cloudwatch-slack-alerts/cmd"
+)
+
+func main() {
+	if err := cmd.NewCommand().Execute(); err != nil {
+		os.Exit(1)
+	}
+}
diff --git a/payloads/alarm.json b/payloads/alarm.json
new file mode 100644
index 0000000..377a1e0
--- /dev/null
+++ b/payloads/alarm.json
@@ -0,0 +1,42 @@
+{
+  "source": "aws.cloudwatch",
+  "alarmArn": "arn:aws:cloudwatch:us-east-1:444455556666:alarm:lambda-demo-metric-alarm",
+  "accountId": "444455556666",
+  "time": "2023-08-04T12:36:15.490+0000",
+  "region": "us-east-1",
+  "alarmData": {
+    "alarmName": "lambda-demo-metric-alarm",
+    "state": {
+      "value": "ALARM",
+      "reason": "test",
+      "timestamp": "2023-08-04T12:36:15.490+0000"
+    },
+    "previousState": {
+      "value": "INSUFFICIENT_DATA",
+      "reason": "Insufficient Data: 5 datapoints were unknown.",
+      "reasonData": "{\"version\":\"1.0\",\"queryDate\":\"2023-08-04T12:31:29.591+0000\",\"statistic\":\"Average\",\"period\":60,\"recentDatapoints\":[],\"threshold\":5.0,\"evaluatedDatapoints\":[{\"timestamp\":\"2023-08-04T12:30:00.000+0000\"},{\"timestamp\":\"2023-08-04T12:29:00.000+0000\"},{\"timestamp\":\"2023-08-04T12:28:00.000+0000\"},{\"timestamp\":\"2023-08-04T12:27:00.000+0000\"},{\"timestamp\":\"2023-08-04T12:26:00.000+0000\"}]}",
+      "timestamp": "2023-08-04T12:31:29.595+0000"
+    },
+    "configuration": {
+      "description": "Metric Alarm to test Lambda actions",
+      "metrics": [
+        {
+          "id": "1234e046-06f0-a3da-9534-EXAMPLEe4c",
+          "metricStat": {
+            "metric": {
+              "namespace": "AWS/Logs",
+              "name": "CallCount",
+              "dimensions": {
+                "InstanceId": "i-12345678"
+              }
+            },
+            "period": 60,
+            "stat": "Average",
+            "unit": "Percent"
+          },
+          "returnData": "True"
+        }
+      ]
+    }
+  }
+}
diff --git a/payloads/composite.json b/payloads/composite.json
new file mode 100644
index 0000000..8d402ec
--- /dev/null
+++ b/payloads/composite.json
@@ -0,0 +1,30 @@
+{
+  "source": "aws.cloudwatch",
+  "alarmArn": "arn:aws:cloudwatch:us-east-1:111122223333:alarm:SuppressionDemo.Main",
+  "accountId": "111122223333",
+  "time": "2023-08-04T12:56:46.138+0000",
+  "region": "us-east-1",
+  "alarmData": {
+    "alarmName": "CompositeDemo.Main",
+    "state": {
+      "value": "ALARM",
+      "reason": "arn:aws:cloudwatch:us-east-1:111122223333:alarm:CompositeDemo.FirstChild transitioned to ALARM at Friday 04 August, 2023 12:54:46 UTC",
+      "reasonData": "{\"triggeringAlarms\":[{\"arn\":\"arn:aws:cloudwatch:us-east-1:111122223333:alarm:CompositeDemo.FirstChild\",\"state\":{\"value\":\"ALARM\",\"timestamp\":\"2023-08-04T12:54:46.138+0000\"}}]}",
+      "timestamp": "2023-08-04T12:56:46.138+0000"
+    },
+    "previousState": {
+      "value": "ALARM",
+      "reason": "arn:aws:cloudwatch:us-east-1:111122223333:alarm:CompositeDemo.FirstChild transitioned to ALARM at Friday 04 August, 2023 12:54:46 UTC",
+      "reasonData": "{\"triggeringAlarms\":[{\"arn\":\"arn:aws:cloudwatch:us-east-1:111122223333:alarm:CompositeDemo.FirstChild\",\"state\":{\"value\":\"ALARM\",\"timestamp\":\"2023-08-04T12:54:46.138+0000\"}}]}",
+      "timestamp": "2023-08-04T12:54:46.138+0000",
+      "actionsSuppressedBy": "WaitPeriod",
+      "actionsSuppressedReason": "Actions suppressed by WaitPeriod"
+    },
+    "configuration": {
+      "alarmRule": "ALARM(CompositeDemo.FirstChild) OR ALARM(CompositeDemo.SecondChild)",
+      "actionsSuppressor": "CompositeDemo.ActionsSuppressor",
+      "actionsSuppressorWaitPeriod": 120,
+      "actionsSuppressorExtensionPeriod": 180
+    }
+  }
+}